1. Technical Field
The disclosure relates to an audio device and an audio input/output method, and more particularly to an audio device capable of saving a capacitor and an audio input/output method thereof.
2. Related Art
An audio system has a so-called re-tasking mechanism, that is, the same audio port may be set by a user according to actual requirements to input or output an audio signal. In other words, the audio port is capable of both inputting and outputting an audio signal.
In the conventional re-tasking mechanism, the audio port is connected to two operational (OP) amplifiers respectively, these being an output OP amplifier and an input OP amplifier. For both the output and input OP amplifier external circuits of the two amplifiers are respectively connected to one large capacitor or share one large capacitor, and direct current (DC) components in the audio signals are then filtered by the respectively connected capacitors or the shared large capacitor, such that the capacitors may be called DC blocking capacitors.
However, whether or not the structure requires that the output or the input amplifier be respectively connected to one capacitor, or the structure requires that the output and the input amplifier share one capacitor having a relatively large capacitance, the amplifiers place a high demand on the number of capacitors or on the capacitance of the shared capacitor, resulting in an undesirable cost. Further, the DC blocking capacitor may easily cause popping noises during outputting, and thus an external OP amplifier is generally added to eliminate the popping noises, increasing costs.
Therefore, there is an urgent need for solutions to eliminate the problems derived from the audio port having input and output functions in the audio system, so as to obtain a desired audio quality.